套管井超声导波成像系统开发与工程应用研究

针对现有套管井检测与评价技术存在的缺陷,开展了进一步的导波成像方法与技术开发研究。对套管壁A0导波模式频散与泄漏衰减特性,以及泄漏衰减特性与管外粘结材料特性阻抗的关系进行了分析。在此基础上进行了不同粘结载荷钢板模型A0模泄漏衰减等特性以及脉冲回波厚度共振波特性的实验测试。结果显示,结合A0模式的衰减与管外粘结材料特性阻抗的测试结果,可有效定征管外粘结材料特性,进一步确定和成像管外环形空间水力联通特性。以此为基础,开发了耐温和耐压宽带超声换能器,以及检测与成像系统。通过模型井和实际井的测试,获得良好效果。

Development and application for ultrasonic imaging system based on guided waves in cased boreholes

The research and development on imaging technique based on guided waves are further conducted to existing problems of current detecting and evaluation techniques in cased boreholes. The properties of dispersion and leaky attenuation of A0 mode in a steel plate, as well as the relation between the leaky attenuation and characteristic impedance of the materials bonded to the back surface of this steel plate, are analyzed. Further experimental testing for the leaky attenuation of A0 mode and the properties of thickness resonance mode are conducted for a steel plate, to which one side loaded with water and the other side bonded with different materials. The results show that the properties of materials in annular space between the steel casing and formation can be characterized effectively using the leaky attenuation of A0 mode and the characteristic impedance of the materials outside the casing obtained from thickness resonance measurement, and the hydraulic communication status can also be evaluated accordingly. Based on these results, we designed and developed the temperature and pressure resisting ultrasonic transducers, as well as detecting and imaging system for cased borehole logging and evaluation. The logging results in model testing wells agree well with the actual situations, and the good results also are obtained in cased boreholes in oilfields.